The NanoVNA DOES have a setting to display SWR. It just generates its own signal to measure it; it doesn't connect to a transmitter. The same with the RigExpert AA-600. It generates its own signal to display the SWR over the frequency range you choose. Last year I used the NanoVNA to measure the SWR of a small magnetic loop antenna wound on a ferrite bar and used in the 400 to 600 kHz range. And I've used it in SWR mode to tune loop Yagis for 902 and 1296 MHz. Zack W9SZ On Wed, Jul 20, 2022 at 12:50 PM W0LEV <davearea51a@...> wrote: Any amateur radio operator using a NANOVNA (or even the TinySA) should
absolutely know it's a low-power device and not fit for inline or
terminating installation!!!!!!! It ain't no Bird Wattmeter!!!!!!! If one
is not familiar with these sorts of test equipment, read the "welcome mat"
or "quick start" guide that is included in the box with all of them I've
bought (too many) well before even charging the unit(s)!!
Please.......please.........where did common sense go???? I know. Common
sense is not common and it is no longer taught.
Dave - W?LEV
On Wed, Jul 20, 2022 at 12:18 PM DougVL <K8RFTradio@...> wrote:
On Thu, Jul 14, 2022 at 07:56 PM, Ken wrote:
Be careful about suggesting using nanoVNA as an SWR Meter. Most SWR
Meters are
used between a transmitter and an antenna to show the SWR in the transmission
line at an operating frequency. The nanoVNA is connected to a transmission
line and antenna to show what the SWR will be when fed from a transmitter at
various frequencies. It would lead to disaster if someone connected a nanoVNA
between a transmitter and antenna.
That's another good reason or feature of the Nano's price! If you blow it
up (by transmitting into it), it probably won't break the bank. BUT if the
transmitter blows up too, well then you'll wish you looked (and learned)
before you jumped.
--
Doug, K8RFT
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
<> Virus-free. www.avg.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
|
Any amateur radio operator using a NANOVNA (or even the TinySA) should
absolutely know it's a low-power device and not fit for inline or
terminating installation!!!!!!! It ain't no Bird Wattmeter!!!!!!! If one
is not familiar with these sorts of test equipment, read the "welcome mat"
or "quick start" guide that is included in the box with all of them I've
bought (too many) well before even charging the unit(s)!!
Please.......please.........where did common sense go???? I know. Common
sense is not common and it is no longer taught.
Dave - W?LEV
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Show quoted text
On Wed, Jul 20, 2022 at 12:18 PM DougVL <K8RFTradio@...> wrote: On Thu, Jul 14, 2022 at 07:56 PM, Ken wrote:
Be careful about suggesting using nanoVNA as an SWR Meter. Most SWR
Meters are
used between a transmitter and an antenna to show the SWR in the transmission
line at an operating frequency. The nanoVNA is connected to a transmission
line and antenna to show what the SWR will be when fed from a transmitter at
various frequencies. It would lead to disaster if someone connected a nanoVNA
between a transmitter and antenna.
That's another good reason or feature of the Nano's price! If you blow it
up (by transmitting into it), it probably won't break the bank. BUT if the
transmitter blows up too, well then you'll wish you looked (and learned)
before you jumped.
--
Doug, K8RFT
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
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Re: SMA to banana binding post
Good afternoon Dave,
Do you know whether those copper blanks are available anywhere that can be
bought? I have tried making some with not much success.
Fred - N4CLA
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On Wed, Jul 20, 2022 at 1:12 PM W0LEV <davearea51a@...> wrote: SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote:
Anyone has or seen an sma male to an open banana binding post to connect
to components ?
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
|
The NANOVNA can be used directly at 300-ohm resistance. Careful
calibrationn and placement of the cursor is required to ultimately read
values is required, but can be accomplished without introducing another
piece of uncertainty.
Dave - W?LEV
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On Wed, Jul 20, 2022 at 4:01 AM Observer <tvstreamdevice@...> wrote: Anyone has used the nano with an antenna bridge ( or noise bridge ?) to
measure antenna impedances other than 50 ohms, like 300 ohms and up ?
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
|
Re: SMA to banana binding post
SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
toggle quoted message
Show quoted text
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote: Anyone has or seen an sma male to an open banana binding post to connect
to components ?
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
|
New users of the NanoVNA have many questions about their new piece of test equipment. They will find a lot of useful information and User Guides in the Files section of this group. /g/nanovna-users/filesAnswers to common questions and how to information in this group's Wiki /g/nanovna-users/wikiOver the years most questions have been answered more than once by other members. Just use the search feature of groups.io to find previous relevant posts in this group. Roger
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Re: SMA to banana binding post
On 7/20/22 8:44 AM, Observer wrote: Anyone has or seen an sma male to an open banana binding post to connect to components ?
Typically, I use a BNC-dual banana jack and a SMA/BNC adapter. I don't know that anyone sells a SMA-Banana I've built them over the years. Usually, by cutting a SMA-SMA cable, splitting the coax and using a dual jack or plug - or by using individual jacks or plugs on the two conductors. To get a decent calibration (if needed) you want to anchor the wires to the binding posts, so that they don't move.
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On 7/20/22 7:08 AM, Observer wrote: I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
In general yes. The miniVNA uses a different receiver design, and different ways of sampling the signals, but the basic concept is the same - look at reflected signal vs incident signal. Calibration done a similar way. I looked through the first part of that writeup and it all looks like straightforward stuff.
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On Wed, Jul 20, 2022 at 07:08 AM, Observer wrote:
I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
Yes
|
Re: SMA to banana binding post
Try reading this groups's Wiki to learn more about testing jigs to measure components.
Roger
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SMA to banana binding post
Anyone has or seen an sma male to an open banana binding post to connect to components ?
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yes,
now go measure with your nano if you have one.
What is your name? (second time I ask)
Op 20-7-2022 om 16:08 schreef Observer:
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Show quoted text
I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
|
I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
|
On Thu, Jul 14, 2022 at 07:56 PM, Ken wrote:
Be careful about suggesting using nanoVNA as an SWR Meter. Most SWR Meters are
used between a transmitter and an antenna to show the SWR in the transmission
line at an operating frequency. The nanoVNA is connected to a transmission
line and antenna to show what the SWR will be when fed from a transmitter at
various frequencies. It would lead to disaster if someone connected a nanoVNA
between a transmitter and antenna.
That's another good reason or feature of the Nano's price! If you blow it up (by transmitting into it), it probably won't break the bank. BUT if the transmitter blows up too, well then you'll wish you looked (and learned) before you jumped. -- Doug, K8RFT
|
On 7/19/22 9:00 PM, Observer wrote: Anyone has used the nano with an antenna bridge ( or noise bridge ?) to measure antenna impedances other than 50 ohms, like 300 ohms and up ?
I don't think you want to use them together. The NanoVNA directly measures impedance vs frequency. Yes, the usual display is S11 referred to 50 ohms, but you can convert that to R and X (and, in fact, it will do that for you) No reason why it won't measure 300 ohms.
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On 7/20/22 2:13 AM, Ed G8FAX wrote: Is there a performance specification for the nanoVNA?
Particularly interested in V4.2 HW version as I have one
Kind regards I don't know that there's published specifications - it's more "we built it, you use it, as found" There's a fair amount of lore - measurements people have made, etc. It's kind of different from buying a VNA from, say, Keysight where they have a published spec sheet, acceptance tests, etc. That is part of what makes the FieldFox cost 100x what the NanoVNA costs. Practically speaking, it puts out about 0 dBm, has about 60 dB dynamic range (sometimes as much as 80 dB), covers 50 kHz up to at least 900 MHz (some versions cover more), has 101,201, or 401 points in a sweep (depend on software version).
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On 20/07/2022 11:14, Arie Kleingeld PA3A wrote: I've measured in the HF range only.
Low and high impedances, testing with resistors.
The results are in the following documents:
73,
Arie Most interesting, Arie, thanks for posting. Judging by your plots, I'd say the 1-ohm to 470-ohms range is quite acceptable. More complex, though for someone wanting to measure antennas! 73, David GM8ARV -- SatSignal Software - Quality software for you Web: Email: david-taylor@... Twitter: @gm8arv
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I've measured in the HF range only.
Low and high impedances, testing with resistors.
The results are in the following documents:
73,
Arie
Op 20-7-2022 om 11:24 schreef David J Taylor via groups.io:
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On 20/07/2022 10:19, alex wrote:
In my possible dumb imagination I would use a 10 or 20 dB attenuator to avoid mismatch on the NanoVNA side. Then measure the impedance. Then I would make an a-symmetrical attenuator from 50 to that first guess en measure again. This would only require some resistors. Or am I wrong?
73 Alex. PE1EVX I think that would make high/low measurements much less accurate!
To the OP: As a suggestion, anything more than, say, 5 times from the nominal
50 ohms will be subject to increasing inaccuracy.? Say 10 - 250 ohms you might
be OK?? Perhaps someone might like to confirm this?? Perhaps better if you use
a 4:1 transformer - the appropriate way round?
73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web:
Email: david-taylor@...
Twitter: @gm8arv
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Roger Need
Arie Kleingeld PA3A
David J Taylor